Gavin Vitt, 39 and looking fit and clean-cut in a sky-blue Daily Harvest Aquaponics polo shirt, motions to a large diagram on the drywall of his break room, just past the entryway of an east-side office park.

Vitt is illustrating "the aquaponic nitrogen cycle" among fish, their waste, beneficial bacteria and edible plants. In the adjoining warehouse, the cycle plays out: In a series of gravity-fed tanks, nutrient-rich water moves from our finned friends to greenery whose roots finger deeply underwater through holes cut in floating foam boards. Once it's lost its nitrogen elements, the water then is sent back to the striped bass and tilapia.

Besides the fish, Vitt is raising romaine and Lollo Rossa lettuce here, and Swiss chard, kale, citrus and Genovese basils, cilantro and mint. All of it is being cultivated with local chefs in mind.

And all of it makes for a huge gamble.

Aquaponics — a combination of fish-raising and hydroponic farming, yielding both vegetables and animal protein — is not altogether new. But Vitt is taking something that's conventionally managed outdoors in a greenhouse and bringing it inside a warehouse, building an almost Disney-esque circle of life in order to beat winter. He's spending tens of thousands of dollars on lighting, but betting he'll make it back — and then some — by creating a continuous production run that demands just one heater for each of his tanks; achieves "bio-security" by shutting out caterpillars, aphids and other pests; and uses 90 percent less water than people who farm in soil.

"Water in Colorado is the new gold," he tells a small tour group that includes area culinary students, who whisper to each other about ways they'd use his citrus basil and bok choy. He tells them that they are the future chefs with whom he hopes to work once Daily Harvest Aquaponics has grown to its capacity — which he says will be soon, capable of selling around 60 fish a week and 220 heads of lettuce daily.

With his tilapia hatchlings hailing from Cañon City and his striped bass fingerlings from Longmont, his fish promise to be the most local option around, particularly during cold months. And the converted 9,500-square-foot warehouse, 2,700 feet of it devoted to growing space, already bursts with vibrant greenery.

"Going inside a warehouse, that's perfect in terms of controlling your environment," says outdoor aquaponics farmer Charles Hendrix of nearby Abundant Harvest Aquaponics. "But" — and here come the key questions — "how do you replicate in sufficient quality and quantity the sun? How efficient is it as a business model?"

Vitt's no absent-minded angler; he couldn't be. The balancing of fish to plants to beneficial bacteria is an exacting science.

"To make an operation successful," explains Hendrix, "it's the nuances you learn every single day: 'Why do I have aphids? Why did I lose three fish in two days? ... Is bad bacteria in play? Is there enough good bacteria? Is the filtration system where it needs to be?' It's those nuances that make any operation a success."

Vitt's system works like this: His tilapia and striper, and a few koi for clean-up, swim in continually recirculated fresh water that's pulled by gravity through tubes in the bottom of each tank. From there it moves into more tanks to filter out solids through plastic baffles and bunched bird netting; beneficial bacteria converge there, converting ammonia into nitrates. The nitrates move down the line and act as fertilizer for the plants. Once the water's zapped of its nutrients, it's sent into a final conditioner and heater for return to the fish.

Vitt allots two gallons of water per fish in 500-gallon tanks, 15,000 gallons total, with the hatchlings beginning in a smaller system. His plant seeds mature for 12 days in trays made from refined basalt rock and chalk, then in PVC arrays for another 12 days while they feed off the fish-nutrient water. Next they head to those polystyrene boards, where each day they're floated one tray closer to harvest at the pool's far end. Babies grow to bouquets in six to seven weeks, in a stair-stepping lineup.

During the tour, Pete Aiello, executive chef at the DoubleTree by Hilton, comes by, white coat and all, to check on the bass that he plans to place on his menu as soon as they're ready. While on-site, he talks about the butterhead lettuce he's sampled, which is growing gangbusters.

"The shelf life is incredible," says Aiello, noting that a head he left in his refrigerator crisper still stood up after three weeks. "There's such a high water content because of how it's grown. It's really full of flavor and moisture. It's got a nice crunch."

By the time other lettuces arrive from California or elsewhere, Aiello says, they're already many days removed from the ground and typically must be eaten right away or tossed. Beyond being local and naturally grown, Vitt's products can help eliminate food waste. Some restaurants toss up to 10 percent of their purchases, contributing to the 30 to 40 percent of the overall U.S. food supply that's squandered, according to the National Restaurant Association and the U.S. Department of Agriculture.

Not only do local aquaponics reduce carbon footprints and yield prolonged freshness, they offer a more sustainable protein source, considering that industrial animal agriculture, via methane from cows and the like, is purported to produce more greenhouse gases than all forms of transportation combined, according to the Food and Agriculture Organization of the United Nations.

And aquaponics doesn't rely on the petroleum-based fertilizers and environmentally destructive pesticides typically used by Big Ag — which is one reason Vitt decided to learn the trade. For years, his family operated Lawn Doctor locations in the Springs and Pueblo, using chemicals to treat people's yards. When he attended a four-day class last year in Wisconsin at Nelson and Pade, an aquaponics industry leader, he saw it offered a different path.

Vitt's family has sold both businesses. Now, in former warehouse space off Marksheffel Road — where a wooden Lawn Doctor sign still hangs askew, its green-thumb graphic pointing downward — his parents assist him and his wife part-time with feeding, seeding, transplanting and harvesting. Vitt's children are learning to test water levels and enjoy feeding the fish and taste-testing the produce.

"We're truly a family-run farm," he says.

Despite all the good, it's not all good so far. While on site, Aiello inquires about a test batch of mache (lamb's lettuce) Vitt had attempted. Vitt shakes his head with a disappointed grimace, saying the mache didn't prefer his system, that it wasn't advancing from a weak, spindly stage.

It's not for lack of trying, according to Larry Stebbins of Pikes Peak Urban Gardens, who has consulted with Vitt and served as both enthusiastic booster and constructive critic.

"His work is important, and he's doing it as carefully as anyone I know," says Stebbins, who also is trying to localize and maximize food supply with his own Pikes Peak Small Farms initiative (pikespeaksmallfarms.org). "He's really trying to find the best way to grow the best and healthiest crops using that method."

Stebbins goes on: "He's using organic practices, conserving water and re-purposing a city structure that could otherwise lay vacant. But do the finances justify the activity?"

Vitt declines to say how much he's spent on all of his efforts to date. But once you tally the costs of 40 650-watt LED lights, a massive network of PVC piping, giant plastic tanks, pumps, heaters, and sprouting equipment, it'd be fair to presume he's well over $100,000 for the equipment alone.

Investments such as the LED lighting capable of adjusting between red, blue and white spectrum for crop optimization could pay off in lesser maintenance and longer life than conventional lighting. Unlike marijuana growers who can gobble $8,000 of electricity monthly on the low end, Vitt offers that his electric bill is only around $2,000 a month.

Still, that's double what Adam Brock, director of operations at Denver's GrowHaus, says he spends per month between November and April in his 20,000 square feet of greenhouse space in northeast Denver, which houses a 3,200-square-foot aquaponics array. GrowHaus operates as a nonprofit, and Brock says community support has been instrumental to its success.

Asked about a for-profit model, he says, "I do think that at the right scale and with the right skill set, aquaponics can be commercially viable outside of the nonprofit sector." But when it comes to profitability, he adds, "there's a very fine line. ... There's a saying in the industry: If you haven't killed a few thousand fish, you haven't earned your aquaponics stripes yet."

One way to size up the task is to contrast Vitt with Abundant Harvest's Hendrix, who speaks on the challenges of greenhouse farming. Hendrix, 66, owned a chain of sports memorabilia stores before going into farming in 2010 with a commitment to give 50 percent of crops to local food banks. The drought of 2012 put him out of business on a property in Security-Widefield, but then a friend pointed him to an aquaponics seminar in Berthoud. It "changed my life," he says. "I saw the sustainability and impact on the environment and it was the only way to go for me."

He began building a 3,000-square-foot greenhouse in April 2013, finishing by August and producing his first crop in October. He's even perfected how to grow a kiwi in his system, which made him so excited he couldn't wait for them to reach full maturity: "They were so sweet and good!"

Hendrix also acquired a license from the state to become a fish breeder in order to create another revenue stream, whereas Vitt prefers to purchase his hatchlings each time to "maintain control over the size of each generation."

What Hendrix didn't do was build a structure capable of making it through winter, meaning he lost 200 fish during a cold spell this past spring. Tilapia thrive in water between 60 and 80 degrees and an ambient air temperature just over 70 degrees, he says, noting it would cost more to heat his giant hoop tunnel of double-layered plastic than the structure is worth.

"I have to shut down at this time of year and start back up in April, which defeats the whole purpose," he says. But this was only his concept building, and he's soon to launch a crowd-funding initiative for a new, energy-efficient aquaponic greenhouse that he hopes to partner with local schools, including colleges.

"I'd never go [into a warehouse], based on what I've learned," he says. "It can be done, but money is the question. If you have the resources, you can replicate the natural elements. This is 2014 — they can create anything."

Indeed, the economic climate remains uncertain for risk-takers and dreamers. Vitt will need to monetize his outfit at every turn, including beginning to charge for tours soon and turn his sludge (fish poop extracted from filters) into organic fertilizer for urban gardeners. But just as he's meticulously measured water and nitrogen levels daily, Vitt says he has calculated costs and revenue several years out. He believes profits will become another extraction from the loop within three to four years.

"Nobody has written the handbook for growing inside," Vitt says, "but I'm going to try to write the book and make this profitable."

If he can, it'll be just the type operation local chefs and restaurateurs have been calling for to address the cold season, and a nice complement to upcoming ventures like the Colorado Springs Public Market. There's a clear resolve in the locavore zeitgeist to make truly local food happen now. And what better system than one that mostly feeds itself while feeding us?